(x-10)(x+10)=-91

Solution for (x-10)(x+10)=-91 equation:

Simplifying
(x + -10)(x + 10) = -91

Reorder the terms:
(-10 + x)(x + 10) = -91

Reorder the terms:
(-10 + x)(10 + x) = -91

Multiply (-10 + x) * (10 + x)
(-10(10 + x) + x(10 + x)) = -91
((10 * -10 + x * -10) + x(10 + x)) = -91
((-100 + -10x) + x(10 + x)) = -91
(-100 + -10x + (10 * x + x * x)) = -91
(-100 + -10x + (10x + x2)) = -91

Combine like terms: -10x + 10x = 0
(-100 + 0 + x2) = -91
(-100 + x2) = -91

Solving
-100 + x2 = -91

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '100' to each side of the equation.
-100 + 100 + x2 = -91 + 100

Combine like terms: -100 + 100 = 0
0 + x2 = -91 + 100
x2 = -91 + 100

Combine like terms: -91 + 100 = 9
x2 = 9

Simplifying
x2 = 9

Take the square root of each side:
x = {-3, 3}